Electronic displays such as Liquid Crystal Displays (LCD) utilize power supply circuits to power various aspects of the display. The power supply circuits can include powering displays, controlling backlighting, and generating gamma voltages, for example. The displays can include various form factors and technologies that must be integrated with the power supply circuits. The display power supply circuits can include LCD bias circuits, level shifters, scan drivers, and LCD bias integrated with level shifters, for example.
One common circuit configuration for driving a display involves providing output power from the power supply circuit through a power switching device to power the display such as in a display bias application, for example. The output lead of the power switching device is typically coupled to the display and the input lead of the device is typically coupled to a low-forward voltage device such as a Schottky diode which in turn is coupled to a switching inductor for a power supply. The control lead of the power switching device is typically connected to ground during normal display bias operations to enable full power to be delivered through the power switching device to the display. Unfortunately, this type of configuration can cause damage to the power switching device. If the output voltage at the output lead of the power switching device were accidentally shorted to ground, for example, excessive current can flow through the power switching device which could potentially destroy the device.